Medication-Wide Study: Exploring Medication Use 10 Years Before a Diagnosis of Inflammatory Bowel Disease

Abstract

Objectives There is growing interest in the pre-diagnostic phase of inflammatory bowel disease (IBD) and in the overlap of IBD with other diseases. We described and compared use of any prescription medication between individuals with and without IBD in a ten-year period preceding diagnosis. Methods Based on cross-linked nationwide registers, we identified 29,219 individuals diagnosed with IBD in Denmark between 2005 and 2018 and matched to 292,190 IBD-free individuals. The primary outcome was use of any prescription medication in years 1-10 prior to IBD diagnosis/matching date. Participants were considered as medication users if they redeemed ≥1 prescription for any medication in the WHO anatomical therapeutic classification (ATC) main or subgroups before diagnosis/matching. Results The IBD population had a universally increased use of medications compared to the matched population prior to IBD diagnosis. At ten years before diagnosis, the proportion of users was 1.1- to 1.8-fold higher in the IBD population in 12 of 14 ATC main groups of medication, p-value <0.0001. This applied across age, sex, and IBD subtypes, although most pronounced for Crohn’s disease (CD). Two years prior to diagnosis, the IBD population had a steep increase in medication use for several organ systems. When analyzing therapeutic subgroups of medication, the CD population exhibited 2.7, 2.3, 1.9, and 1.9 times more users of immunosuppressants, antianemic preparations, analgesics, and psycholeptics than the matched population ten years prior to diagnosis (p-value <0.0001). Conclusions Our findings demonstrate universally increased medication use years before IBD, especially CD, and indicates multiorgan involvement in IBD.